Mobile communication systems were developed to provide the subscribers with voice communication services on the move. Recently, the mobile communication systems have evolved beyond the early voice-oriented services to the level of supporting high speed data communication services. However, resource shortages and user requirements for higher speed services are spurring evolution towards increasingly more advanced mobile communication systems.
As one of the next-generation mobile communication systems for meeting such requirements, the 3rd Generation Partnership Project (3GPP) has standardization underway for a Long Term Evolution (LTE) system. LTE is a technology designed to provide high speed packet-based communication of up to 100 Mbps and aims at commercial deployment around a 2010 timeframe. In order to accomplish this aim, a discussion is being held on several schemes: for example, one scheme for reducing the number of nodes located in a communication path by simplifying a configuration of the network and another scheme for maximally approximating wireless protocols to wireless channels.
In order to meet the wireless data traffic demand that has grown since the commercialization of 4th Generation (4G) communication systems, many studies have been conducted to develop an enhanced 5G or pre-5G communication system. For this reason, the 5G or pre-5G communication system is also called a beyond-4G communication system or a post Long Term Evolution (LTE) system. Consideration is being given to implementing the 5G communication system in millimeter wave (mm Wave) frequency bands (e.g., 28 GHz and 60 GHz bands) to accomplish higher data rates. In order to increase the propagation distance by mitigating propagation loss in the 5G communication system, discussions are underway about various techniques such as beamforming, massive MIMO, Full Dimensional MIMO (FD-MIMO), array antenna, analog beamforming, and large scale antenna. Also, in order to enhance network performance of the 5G communication system, developments are underway of various techniques such as evolved small cell, advanced small cell, cloud Radio Access Network (RAN), ultra-dense network, Device to Device (D2D) communication, wireless backhaul, moving network, cooperative communication, Coordinated Multi-Points (CoMP), and interference cancellation. Furthermore, the ongoing research includes the use of Hybrid FSK and QAM modulation and Sliding Window Superposition Coding (SWSC) as Advanced Coding Modulation (ACM), Filter Bank Multi Carrier (FBMC), Non-Orthogonal Multiple Access (NOMA), and Sparse Code Multiple Access (SCMA).
Meanwhile, the Internet is evolving from a human-centric communication network in which information is generated and consumed by humans to the Internet of Things (IoT) in which distributed things or components exchange and process information. The combination of the cloud server-based Big data processing technology and the IoT begets Internet of Everything (IoE) technology. In order to secure the sensing technology, wired/wireless communication and network infrastructure, service interface technology, and security technology required for implementing the IoT, recent research has focused on sensor network, Machine to Machine (M2M), and Machine Type Communication (MTC) technologies. In the IoT environment, it is possible to provide an intelligent Internet Technology that is capable of collecting and analyzing data generated from connected things to create new values for human life. The IoT can be applied to various fields such as smart home, smart building, smart city, smart car or connected car, smart grid, health care, smart appliance, and smart medical service through legacy Information Technology (IT) and the convergence of various industries. Thus there are various attempts to apply the IoT to the 5G communication system. For example, sensor network, Machine to Machine (M2M), and Machine Type Communication (MTC) technologies are implemented by means of the 5G communication technologies such as beamforming, MIMO, and array antenna. The application of the aforementioned cloud RAN as a big data processing technology is an example of convergence between the 5G and IoT technologies.
In such a mobile communication system, it may be possible for a terminal to use multiple heterogeneous networks. In particular, it may be possible for the terminal to use a 3GPP access network such as GERAN/UTRAN/E-UTRAN and a non-3GPP access network such as Wireless Local Area Network (WLAN). For example, the user terminal may access an E-UTRAN and a WLAN simultaneously for data communication; therefore, there is a need of a method and apparatus for the network to control the user terminal optimally in consideration of subscriber information and network condition.